The aim of the proposed project is to establish the feasibility of developing the techniques and the instrumentation that will enable EPR dosimetry, based on measurements of teeth in vivo, to be at a state where it can be used by non-expert personnel in the field in response to radiation events where large numbers of people have potentially had significant exposures to ionizing radiation. Ongoing studies at Dartmouth have demonstrated the safety of EPR tooth dosimetry and its ability to quantify individual exposures to ionizing radiation. However, the devices currently in use are typical of laboratory equipment, requiring expert operators and a complicated, multi-step measurement and analysis process. In addition there have not been systematic studies of variables that are likely to affect measurements in real populations under field conditions such as tooth size and shape, the impact of significant dental work, and demographic differences (such as age, gender, race). To show the feasibility of EPR tooth dosimetry with non-expert users under practical field conditions, the study will: (i) develop hardware and software solutions automating the measurement process;(ii) develop experimental data on the impact of individual differences;and (iii) develop sophisticated sampling and modeling techniques to account for individual differences. The studies will be carried out in collaboration with the Dartmouth EPR Center where, under a subcontract, the unique equipment and experience at Dartmouth will be used to develop experimental data that can be used to account for individual variations;advise on the development of modeling and software to account for individual variations, including testing software models developed by Clin-EPR;to consult on the development of hardware solutions for automating and simplifying measurement processes;and in conjunction with Clin-EPR to implement and test these hardware solutions. Achievement of these goals will enable a second phase of the project in which we will produce a fully functional prototype instrument with capabilities and procedures that will be suitable for operation under field conditions by non-expert operators to assist in the triage of populations that have potentially been exposed to clinically significant amounts of ionizing radiation. Such an instrument could then be prepared in an appropriate form for widespread use to enhance the effectiveness of responses to events in which large numbers of individuals have potentially been exposed to radiation. PUBLIC HEALTH RELEVANCE: The ability to measure individual radiation exposures of people at the site of a recent accident or terrorist event will be a major improvement in the capabilities of the emergency response system to react effectively to the medical challenges created by the potential exposure of large numbers of people to clinically significant levels of ionizing radiation. With the capability of EPR tooth dosimetry to provide after-the-fact estimates of doses to individuals, the medical assets available can be utilized most effectively by identifying those who do not need immediate entry into the health care system and those for whom appropriate and prompt intervention can increase the probability of reducing morbidity and mortality from the exposure to radiation.